Conventionally, an electrical component including a connection portion that establishes an electrical connection by contact has been known, such as a terminal having elasticity, a connector including the terminal, and a substrate including a land. In such an electrical component, there is a possibility that a contact resistance is increased at the connection portion due to an oxidation of a metal surface. At the metal surface, electrons are localized like dangling bonds at a semiconductor surface. Oxygen molecule has two unpaired electrons. It is assumed that the oxygen molecule and the metal share the electrons and the oxygen molecule is adsorbed to the metal surface, and thus the metal surface is oxidized. In other words, the localization of the electrons forms a surface level at the metal surface, and the oxygen molecule having unpaired electrons is trapped by the surface level to oxidize the metal surface.
To manage the above possibility, it has been known to plate a surface of the connection portion by a noble metal such as gold. However, when the noble metal is worn (e.g., fretting wear) due to a relative displacement of the connection portion, that is, a sliding movement of the connection portion, the metal surface is exposed and oxidized. To avoid this situation, a thickness of the plating of the noble metal needs to be increased, and thus the cost is increased.
JP 2014-519157 A, which corresponds to US 2014/0102759 A1, discloses an electrical component to manage the above possibility without using the noble metal. An electrical connection element (i.e., the electrical component) has a connection portion including a core body (i.e., a base) and a cover layer formed at a surface of the core body. The cover layer includes a chemical reducing reagent (hereinafter, referred to as a reductant). The reductant is released from the cover layer as a result of the sliding movement and the released reductant reduces a metal oxide at the surface of the cover layer.